Radius Incoming port forwarding is not working on WAN side router

RouterOS Beginner Basics
1

i have 1 connection with static ip and my mikrotik is client of my main router .
i want to port forwarding RADIUS incoming port 3799 on my Main router
But 3799 port is not working any solution please .

2

You need to forward the port from the upstream router to the LANIP of the Mikrotik on the Upstream Routers LAN ( which is also the WANIP of the MT).
Then you need to port forward on the MT to the device…
https://forum.mikrotik.com/viewtopic.php?t=179343